Corrugated inner cover structure

ABSTRACT

An inner cover structure particularly adapted for use in annealing coils of strip steel or the like in a bell type furnace in which the inner cover comprises a transversely corrugated cylindrical body of relatively thin sheet metal having a closed top and an open bottom. The cylindrical body has secured to the outer surface thereof two or more circumferentially spaced lifting lugs or brackets which are adapted to receive lifting hooks so that the inner cover may be positioned on and removed from a furnace charge by means of an overhead crane or the like. The lifting brackets each comprise a plurality of spaced vertical members of approximately the same gauge metal as the cylindrical body and having their edge portions corrugated to conform to the corrugations of the cylindrical body and welded thereto. Crane hook socket forming members are secured to the vertical members and are adapted to be engaged by the lifting hooks referred to above.

United States Patent Ford [54] CORRUGATED INNER COVER STRUCTURE [72] Inventor: Joseph R. Ford, Lakewood, Ohio [73] Assignee: Lee Wilson Engineering Company Inc., Cleveland, Ohio [22] Filed: Aug. 16, 1971 [21] Appl. No.: 171,992

[52] US. Cl ..263/49, 263/47 [51] Int. Cl ..F27d l/l8 [58] Field of Search ..263/49, 47

[56] References Cited UNITED STATES PATENTS 2,183,785 12/1939 Clark ..263/49 R 2,791,418 5/1957 Edelmann ..263/49 R Primary ExaminerJohn .l. Camby Assistant Examiner-l-larold Joyce Att0rney-Paul S. Sessions et al.

[451 Nov. 21, 1972 [5 7] ABSTRACT An inner cover structure particularly adapted for use in annealing coils of strip steel or the like in a bell type furnace in which the inner cover comprises a transversely corrugated cylindrical body of relatively thin sheet metal having a closed top and an open bottom. The cylindrical body has secured to the outer surface thereof two or more circumferentially spaced lifting lugs or brackets which are adapted to receive lifting hooks so that the inner cover may be positioned on and removed from a furnace charge by means of an overhead crane or the like. The lifting brackets each comprise a plurality of spaced vertical members of approximately the same gauge metal as the cylindrical body and having their edge portions corrugated to conform to the corrugations of the cylindrical body and welded thereto. Crane hook socket forming members are secured to the vertical members and are adapted to be engaged by the lifting hooks referred to above.

3 Claims, 3 Drawing Figures PATENTEDunv 21 I972 INVENTOR. J05P// p CORRUGATED INNER COVER STRUCTURE BACKGROUND OF THE INVENTION This invention relates to inner covers for enclosing charges, such as coils of strip steel, to be annealed in a bell type annealing furnace. These inner covers have a tubular cylindrical body portion closed at its top end and open at the bottom. They are commonly carried by a crane or the like to position them upon the furnace base over the charge and to transport them from place to place in an annealing plant. One embodiment of these inner covers incorporates a transversely corrugated cylindrical body of relatively thin sheet metal, the corrugations serving to add strength and rigidity to the structure. Due to the corrugated outer surface of the body certain difficulties have been experienced in providing suitable lugs or brackets to and from which the crane hooks used to transport the cover may readily be attached and detached. These inner covers are quite large and heavy and the lifting brackets must therefore be strong and rigidly attached. Further, because of the wide range of temperatures to which the inner cover units are subjected during use, the lifting brackets must be able to withstand severe temperature changes without loss of strength or other failure.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a corrugated inner cover of the type referred to having lifting brackets which are firmly secured to the corrugated surface of the inner cover body, which will withstand the expansion and contraction of the inner cover body during use without becoming detached therefrom, and which is of rugged design and relatively inexpensive to manufacture. Generally speaking the lifting lugs or brackets comprise channel members having the edges of the channel sides corrugated to conform to the corrugations of the inner cover body. Two or more of these channel members are mounted on the outer surface of the inner cover body in circumferentially spaced relation and extending generally parallel to the longitudinal axis of the body. The corrugated edges of the channels fit the corrugations of the body and are welded thereto. To avoid weld failure due to different rates of thermal expansion or contraction the channel members are formed of sheet metal having substantially the same gauge or thickness as the metal of the inner cover body. Plates, webs, etc. are secured to the channel members to form a socket which may conveniently receive a crane hook. The lifting brackets are preferably two or more in number and are disposed circumferentially and longitudinally on the outer surface of the inner cover body in such a manner that the cover will be held in a stable condition while being handled by the crane.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a somewhat diagrammatic illustrative view of an inner cover of the type herein referred to equipped with lifting brackets and incorporating the present invention. The view also illustrates a crane spreader having lifting hooks suspended therefrom and in engagement with the lifting brackets of the inner cover.

FIG. 2 is an enlarged fragmentary perspective view illustrating one of the lifting brackets on the outer surface of the inner cover body, the crane hook being shown in phantom lines.

FIG. 3 is a plan view of one of the lifting brackets shown in FIGS. 1 and 2, the inner cover body being indicated in phantom lines.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT Referring now to the drawings, the inner cover C shown in FIG. 1 comprises a cylindrical body 1 formed with transverse corrugations 2 which extend substantially normally to the longitudinal axis of the body. One end of the body 1 is closed by a cover plate 3 and the other end 4 is open to permit the cover to be placed over and removed from a charge which is to be annealed.

As illustrated in FIG. 1, two lifting brackets B are secured in diametrically opposed relation on the outer surface of the body 1 adjacent to and equally spaced from its closed upper end. It will be understood that if desired three or more brackets B could be circumferentially spaced around the body 1. To lift the inner cover C crane hooks H, having inwardly extending and upwardly projecting hook portions 5, are secured to cables 6 which in turn are carried by a spreader S having an eye 7 adapted to be connected to the crane cables by suitable means.

The hook portions 5 of the crane hooks H engage the lifting brackets B so that, when the spreader S is lifted by the crane, the hooks will pick up the inner cover C and it may be transported as desired. When the inner cover is placed over the charge and its lower edge is seated on the furnace base a further lowering of the spreader S will permit the crane hooks H to release themselves from the brackets B so that the lifting rig may be removed.

Brackets B, as seen in FIGS. 2 and 3, each includes a pair of channel members 9 and 10 which have the edges of their side walls 9', 9" and 10', 10" corrugated to fit the corrugations 2 of the inner cover body 1 and are welded to the corrugated inner cover wall throughout their corrugated length. The channel members 9 and 10 extend substantially parallel to the iongitudinal axis of the body 1 and, as seen in the drawings, the thickness or gauge of the metal is substantially the same as that of the body 1. This eliminates substantial differences between the rate of expansion and contraction of the body 1 and the vertical members 9 and 10 and thus prevents weld breakage and failure of the bracket due to heating and cooling of the structure. Further, although the metal of the members 9 and 10 and of the body 1 is relatively thin, the channel form of members 9 and 10, each of which has a pair of corrugated side flanges which has an elongated engagement with the corrugated surface of the body 1 and is welded thereto, provides a very strong and efficient attachment of the lifting brackets B to the inner cover body 1.

A transverse base plate 11, of substantially greater thickness than the metal of the channel members 9 and 10, is welded to the faces of the members 9 and 10 and extends across between them in spaced relation to the outer surface of the body 1. Outwardly projecting webs 12 and 13 are welded to the outer surface of base plate I1 and the face plate member 14, which is welded to the outer edges ribs 12 and 13, completes a crane hook receiving socket or compartment.

As seen in FIGS. 1 and 2 the upwardly extending hook portions 5 of the crane hooks H are adapted to enter the socket formed between the base plate 11 and the face plate 14 of the bracket B and be retained therein without danger of accidental disengagement while permitting ready release when desired.

While the foregoing specification describes one embodiment of the improved corrugated inner cover and lifting lugs or brackets therefore it will be understood that the invention may also be practiced in other forms within the description of the following claims.

I claim:

1. An inner cover including a transversely corrugated cylindrical body and a lifting bracket secured to the corrugated surface of said body, said bracket including a plurality of channel members of substantially the same thickness metal as said body and extending generally parallel to the longitudinal axis of said body, said channel members having the edges of their side walls corrugated to fit the corrugations of said cover and being welded thereto, and crane hook receiving socket means secured to said channel members.

2. An inner cover as described in claim 1 including a plurality of said lifting brackets circumferentially spaced around said cylindrical body and equally spaced from one end thereof.

3. An inner cover having a corrugated cylindrical body closed at one end and open at the other end, the corrugations extending substantially normally to the longitudinal axis of said body, a plurality of channel members mounted on the outer surface of said body and extending parallel to the longitudinal axis of said body, the edges of the side walls of said channel members being corrugated to correspond to and fit the corrugations of said body and the metal of said channel members being of substantially the same thickness as the metal of said body, the edges of said side walls of said channel members being welded throughout their corrugated lengths to the corrugated outer surface of said body, a base plate member extending between and secured to said channel members, a pair of spaced apart outwardly projecting webs secured to said base plate member, and a face plate member extending between and secured to the outer edges of said ribs whereby an open bottom crane hook receiving socket is formed.

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1. An inner cover including a transversely corrugated cylindrical body and a lifting bracket secured to the corrugated surface of said body, said bracket including a plurality of channel members of substantially the same thickness metal as said body and extending generally parallel to the longitudinal axis of said body, said channel members having the edges of their side walls corrugated to fit the corrugations of said cover and being welded thereto, and crane hook receiving socket means secured to said channel members.
 1. An inner cover including a transversely corrugated cylindrical body and a lifting bracket secured to the corrugated surface of said body, said bracket including a plurality of channel members of substantially the same thickness metal as said body and extending generally parallel to the longitudinal axis of said body, said channel members having the edges of their side walls corrugated to fit the corrugations of said cover and being welded thereto, and crane hook receiving socket means secured to said channel members.
 2. An inner cover as described in claim 1 including a plurality of said lifting brackets circumferentially spaced around said cylindrical body and equally spaced from one end thereof. 